Nice image! Used it to have a go at seeing the comet visually tonight, but no joy, just too faint with LP and a low Moon. I think the comet's a fair bit fainter than 10 - the galaxy in your image, NGC7213 is mag 10.1, and was a pretty obvious bright ball of fuzz in the 16" scope. The lower brightness (and surface brightness) of the comet just put it out of reach for me tonight. Would put it somewhere below about mag 11.5-12.
But thanks for the image, as it gave me a new observing challenge and I wouldn't have known about C/2012 X1 otherwise